Wheel dressing means



Jne 5, 1951 F.` E. HAwLEY WHEEL DRESSING MEANS 3 Sheets-Sheet 1 FiledDec. 27. 1946 Y m R W Y O A E M H M n n L E u O V T VEL.- I+- WE D u YUY S Nw LB .Il I`| ||r u nl F um.. .1 \$N%% Nm \Qo, ww/ QQ@ y mw nu mm 8O o o mm V um R w m .J1 w wm mmm Sw mw SNE N15@ LT@ wm Qm um, hh IQ .Sv.wv I mhhml June 5, 1951 F. E. HAWLEY 2,555,852

wHEErJ DRESSING MEANS Filed Deb. 27, 194e NVENTOR 27 iBJYUYn E. HAWLEYWHEEL DRESSING MEANS Filed Dec. 27, 1946 3 Sheets-Sheet 3 32 /05/ lINVENTOR @3* /35 l 1:35317: E. HAWLEY //0 /09 $151. E' F19 '7 (j j15a/ATTORNEY Patented June 5, 1.951

WHEEL DRESSING MEANS Floyd E. Hawley, Devon, Conn., assignor to MooreSpecial Tool` Co. Inc., a corporation of Connecticut ApplicationDecember 27, 1946, Serial No. 718,818

(Cl. 12S- 11) 2 Claims. "i

This invention relates to new and useful improvements in grindingmachines and has particular relation to means for dressing form grindingwheels while in place on a grinding machine and which means is alsouseful for the making of formed diamond loaded abrading wheels for usein the form grinding of cemented tungsten carbide or other toughmaterial.

An object of the invention is to provide in a grinding machine, a wheeldressing means including a wheel dressing diamond or other tool andmeans to manipulate the same together with a wheel crushing roller forcrushing of a grinding wheel to the desired contour, the wheel crushingroller being pivotally mounted and means being provided for rapidlymoving the same to and from the grinding wheel and for adjusting thesame in directions parallel with the axis of the grinding wheel shaft.

Another object is to provide an improved method for the manufacture ofdiamond loaded abrading devices especially adapted for the form grindingof cemented tungsten carbide or the like.

Other objects and advantages of the invention will become apparent froma consideration of the following detailed description taken inconnection with the accompanying drawings wherein a satisfactoryembodiment of the invention is shown. However, it is to be understoodthat the invention is not limited to the details disclosed but includesall such variations and modifications as fall within the spirit of theinvention and the scope of the appended claims.

In the drawings:

Fig. 1 is a front elevational view of an upper portion of a grindingmachine incorporating the features of the invention;

Fig. 2 is a top plan view thereof;

Fig. 3 is an end elevational view of the midportion of the machine;

Fig. 4 is an enlarged front elevational view showing the Crusher rollmounting in relation to ing a longitudinally movable table I I mountedon a saddle I2 movable in directions transverse to those in which thetable is movable. At the rear of the table II and saddle I2 is avertical tool post I3 including a vertically adjustable means or slideI4. This slide is adapted to be raised and lowered by suitable means asby a vertical screw I5 fixed to the slide.

A hand wheel I6 is fixed with relation to and is adapted to rotate abevelled gear I'I meshing with a bevelled gear I8 threaded to the screwor shaft I5. Clearly, on turning of the hand wheel I6, the resultantoperation of the gears I'I and I8 will cause the screw or shaft I5 to beraised or lowered depending on the direction in which the hand wheel isturned and will cause a corresponding movement of the slide I4.

Movable with the slide I4 is a bed or block I9 to kwhich bolts 2lisecure a bracket 2 I, the latter including an upper shelf -like portion22, an angularly disposed front wall portion 23 and a hublike portion 24braced by the wall portion 23 and mounting a shaft 25 to which is fixedan abrasive form grinding wheel 26. It is noted that the wheel 26 islocated over any suitable work holder, as a magnetic chuck 2'I,removably fixed to the table II for movement therewith relative to theabrasive Wheel 26. Thus, the chuck is adapted for the supporting of workto be ground and the moving of such work back and forth beneath theabrasive wheel. Clearly, the Wheel head described is adapted forvertical adjustment with the block I9, relative to the chuck and table,on manipulation of the hand wheel I6.

Mounted on the bracket 2| for movement therewith and with the lentirewheel head is a bracket or extension 28 preferably of channel or otherrigid construction, projecting to one side of the bracket 2l and on itsupper side at its outer end including a table-like portion :29. Thisportion 29 is provided with a series of bolt receiving holes or openings3U adapted for use in fixing clamps or other means in place when suchclamps or other means are used for locating and securing a template inplace, as the template 3l.

Integral with or secured to the upper side of the shelf-like portion 22of the bracket 2l is a block or portion 32 provided with a dove-tail way33 mounting a slide 34. A screw 35 having a hand wheel 36, or otherturning means, lixed thereto is adapted to feed the slide 34 on theblock or portion 32 in directions transverse of the axis of the abrasivewheel mounting shaft 25. Preferably, a micrometer scale 3'I isassociated with the wheel 36 whereby the amount of turning E of thewheel and the amount of feed of the slide 34l is accurately shown sothat the operator will know, as he makes an adjustment of the slide 34,the exact extent of such adjustment.

On the upper side of the slide 34 and fixed thereto or integraltherewith is a block 38 provided on its upper side with a dove-tail way39 having a nut 45 fixed thereto as by means of bolts 4 l. On the blockor portion 38 and adapted for movement along the way 39 is a secondslide 42. Such second slide carries a screw 43 threaded through the nut45 and provided with a hand wheel or manipulating portion 44 adapted foruse in manually turning the screw whereby to feed the slide 42 along theway 3Q in directions transverse to those in which the slide 34 isadjusted on manipulation of the hand wheel 36.

A suitable micrometer scale may be associated' with the hand wheel orportion 44.

Preferably, a suitable locking means, such as 0111 in theY nature of ascrew, is provided to be operated by the hand or finger piece 45 forlocking the slide 42l to the ways 39 in the desired position ofadjustment of said slide. Clearly, on release of; the locking device :l5and manipulation of the handpiece s4 the slide 42 and all parts carriedthereby will be adjusted in directions parallel with the longitudinalaxis of the abrasive Wheel mounting shaft 25.

The slide 52 includes a forwardly directed portion, integral with theslide or xed thereto, comprising a pair of arms ZIB and il at theirouter ends supporting an eye or pivot member 48. As shown, the arms 56and @l are generally below and at the sides of the hand piece fili. TheeyeV or pivot portion `i8 comprises a portion of a main pivot 49suspending a pantograph means generally designated 55 Vfrom the outerend portion of the slide 42.

The` arms of the pantograph means 55 are designated 5l., 52, 53 and 5tand it is pantograph arm 5i which is pivoted at ii-9 to the slide 42.Arm 52 is pivoted to arm 5l in spaced relation to the pivot, 59 as at 55while an intermediate pivot 55 connects` the arms 52 and 55. Inaddition, arms 55 and 5A are pivoted together as 'at 5l and anintermediate pivot 5e connects the arms 5| and 54.

i Vlt is here noted that the intermediate pivots 55 and 58 are of thesame construction and that the pivot 5l is located intermediate the endsof the arm 53. The portion of arm 5i between the pivots 49 and 55 isdesignated 55 and the portion of the arm 53 beyond the pivot 5l isdesignated 55. that of portion Bil determines the ratio of movement of atool to that of movement of a stylus as will appear.

Inl spaced relation to the pivot 55 a shaft 6l is rotatably suspendedfrom the arm 52. Toward its lower end said shaft E6| mounts a toolholder 52 and the relation of the parts is such that under the bestconditions the shaft supports the tool holder at a level to have suchholder present the cutting edge of a tool (as a diamond or other tool)in the exact center line of the grinding wheel 26. y Under someconditions, as when using an octohedronshape of diamond, the cuttingedge may initially be below the center line of the wheel and then as theradius of the diamond is renewed, its cutting edge is higher and finallyis slightly above the center line of the wheel. In the present instance,the tool is sometimes a diamond, as when dressing the, abrasive wheel26, and is sometimes The relation of vthe length of portion 59 to acemented tungsten carbide piece, as when dressing a brass disc as willbe described, although it will be understood that any tool suitable foreither purpose may be used.

From the free or outer end portion of the arm portion (see Figs. 1 and2) a shaft 53 is rotatably suspended. At its lower end shaft 53 carriesa head-like formation 64 including a portion 55 extending radially withrespect to the center line of said shaft and having secured to its lowerend a stylus 6E adapted to be turned with the shaft 53 as an axis and tobe fed across a working face of the template 5i, all as will bedescribed, and for the purpose set forth.

Since the tool holder and stylus are both mounted by the pantographmeans 55, rectilinear movement of the stylus will be duplicated by thetool holder and owing to the relationship of the arm portions 59 and 6B,the movement of the tool holder will be on a reduced scale as comparedywith that of the stylus.

Stylus 65, as Yhere shown, comprises a metal plate secured against thelower end of thehead 64. The forward end of the stylus comprises arounded or circular portion 5l, comprising the active portion of thestylus proper, and the center of the radius of this circular portion isthe longitudinal center of shaft E3. rThe free end portion of armportion is enlarged by a head-like portion 53 in which the verticalstylus carrying shaft 53 has bearing.

The details of the construction of the various pivots 55, 55, 5l and 58are fully set forth in the appli-cation of Frederick C. Victory and JohnRobert Moore, Ser. No. 555,952, filed September 27, 19.44, which issuedas Patent No. 2,452,509, dated October 26, 1948. However, it is herenoted that pivot 55` includes a stud 59, pivot 56 includes a stud 15,pivot 5l includes a stud l I, and pivot 58 includes a stud l2.corresponding with the stud 'EU of pivot 5.5.

On the shank of stud lli` there is mounted a bell crank 'i3 adapted toturn freely about said stud. Fixed to the stud or shaft 63 carrying thestylus 5.6 is a lever 'E4 while ixed to the tool carrying shaft 5l. forturning movement therewith is a lever 15. Bell crank 'i3 includes armsit and' Il of which the arm l5 is connected. with lever l5 by a link 'I8pivoted at its respective ends to ther arm andv lever and similarly alink '[9 is pivoted at its. respective ends to the bell crank arm il andthe'lever 14.

Fixed on the shaft 63 is a hand lever 85. With this construction, itwill be seen that on turning of the shaft 53 (and thus the stylus (it)the lever 'i4 will be shifted and through the link le, bellcrank 'i3and. link '18, will impart a similar movement to the lever 15. As thislever is fixed to the tool carrying shaft 5l, itwill. be understood thatturning of the shaft 55 about its axis results in the exact samemovement of the shaft Si about itsaxis.

"Lhus,` by means ofv the described linkage connecting the stylussupporting shaft 63 andthe tool (diamond) supporting shaft 5I, theangular orientation of the stylus normal to the working face of thetemplate 3l governs that of the diamond or other tool` relative to agiven object, in this case the, face of the wheel or disc being dressed.

, The shaft 6 lf is suspended from the arm 52 and necessarily hasrectilinear movement therewith and also. has turning movement relativethereto as influenced byv the linkage construction above described.However, shaft 6| is actually sup-1 ported independently of arm 52whereby the weight of the pantograph and any force applied thereto willnot and cannot cause movement of the shaft such as to force the toolholder 52 toward the wheel 2B.

This is more fully disclosed in the above mentioned patent oi Victoryand Moore but here the means for the described purpose is shown ascomprising an articulated bracket generally designated 13|. Said bracketincludes arms 82 and 83 of which the arm 32 is mounted to swing horizontally on a pivotal mounting including ear portions 04 secured to orcast with the bracket 2i above described.

Arms B2 and 83 are pivot/ed together as at 85 and it will be understoodthat the entire bracket 8| may be swung horizontally 'through pivotalmounting on the ears all and that the bracket arms may have relativepivotal movement in the pivotal connection 85. 'lhe shaft 5| isrotatable in the bracket arm St but it will be clear that the bracketsupports the said shaft against tilting movement, such as might occur ifonly the pivot l0 was depended upon to support the entire pantographstructure. The weight of the pantograph and any force applied theretowill not cause tilting of the shaft 0i in a manner to carry the toolholder 02 toward the grinding wheel 25.

The structure as above described, with the ein ception of the slide i2and its particular con struction and the particular means for adjustingit, is all more fully set forth in the Victory and Moore patent aboveidentied. It is thought that the operation and mechanism so fardescribed will be understood, but briefly it is pointed out that as thestylus GS is moved with respect to the template 3|, the diamond or othertool carried by the holder S2 will be given the exact same movement withrespect to the wheel 25 or other wheel or disc mounted on the shaft 25.

According to the present invention, combined with the wheel dressingmeans above described is a hardened, shaped crushing roller which may beused for crushing a grinding wheel to the desired contour and accordingto the method of the invention for another purpose. In the presentconstruction, such roller is mounted for swinging movement whereby itmay be readily and quickly moved into and out of operative position andmeans for mounting and positioning the roller and adjusting it areprovided. The roller` is provided of a shape depending upon the shape ofthe abrasive wheel to be crushed, and while for that operation aserrated roller may be used, for the second purpose above suggested, asmooth roller is desired.

According to one method oi use of the crushing roller, the pantographmounted diamond or other tool is iirst used to give the abrasive wheel26 the desired contour. Thereafter the dressed wheel is used to grindthis exact contour into the crushing roller. rThe reverse o the desiredcontour of the grinding wheel may be ground into a hardened, cylindricaldressing roller when but a shallow form is required. Otherwise, thehardened crushing roller should be roughed apprcximately to shape andthen finished ground by the dressed wheel 2F; to the exact reverse contour. In either event, the crushing roll having been ground to thedesired contour, it is moved away from the grinding wheel 20 and themachine used in the customary manner for form grinding.

As the abrasive wheel beings to wear, contact is again establishedbetween the wheel and the hardened crushing roller and the latter isused to dress the abrasive wheel. This latter operation may be repeatedas often as desired until the dressing roller begins to lose its trueshape, whereupon the abrasive wheel is dressed with the diamond or othertool and then used to again dress the crushing roller. In this way, aconsiderable saving is effected on the diamond or other tool since theabrasive wheel between the dressings with the diamond or other tool willbe dressed a number of times by engagement with the crushing roller.

To the desired end, an arm generally designated 30 is pivotally mountedon the bracket 2|. This arm is pivoted intermediate its ends and at itslower end supports a Crusher roller 81 posi tioned to be brought againstthe abrasive wheel 26 and to be swung outwardly away from the same asthe arm is rocked in one direction or the other on its pivotal mounting.The pivotal mounting for the arm 855 is shown in detail in Fig. 6 andwill later be fully described.

At its lower end said arm includes :a cylindrical head-like portion 00the ends of which are closed by bearing plates 89 and Eli! which bearingplates serve to mount a shaft 9| having the crushing roller 8l'removably mounted thereon and located as between washers 02 and held inplace .by nut 93. Between the bearings 80 and 90 the shaft 9| is ofenlarged diameter whereby it includes shoulders 05| engaging suchbearing members to the end that the shaft is held against endwisemovement.

Fixed on the shaft 9| within the head 88 is a worm gear 95 constantlymeshing with a worm connected to be driven by an electric motor 9|. Theshaft of said motor passes through a tubular housing 98 and is pinned orotherwise fastened to a coupling element 09 (see Fig. 5) which islikewise connected by a pin and slot connection |00 with a couplingelement I0| integral or fixed to the worm 96. With this construction itwill be clear that whenever the motor 91 is energized the crushingroller 8l will be driven and the same is driven at a relatively lowspeed.

Threaded through the upper portion of the arm 86 is an adjusting screw|02 the inner rounded end portion |03 of which constantly bears againsta cam |04 formed with or secured to an elongated tube or sleeve |05turnable on a stud |00 threaded into a socket in the face of the bracket2| as shown at |07 (Fig. 7). The sleeve |05 is located between washersit and |l9 and a nut ||0 threaded on the outer end oi the stud |06 maybe reasonably tight against the washer |09 so that the sleeve |05 willbe frictionally held in any position to which it may be turned on thestud. For convenience in turning of the sleeve and thus the cam idd, theformer is provided with an enlarged head-like portion lil.

With the described arrangement, when the sleeve |05 is turned to disposethe high portion of the cam |04 under the rounded end |03 of the screw|02, the arm 86 is rocked in a manner to bring the crushing roller 8linwardly into engagement with the abrasive wheel 20. When the lowportion of the cam is under the inner end of the screw |02, the arm 86may rock in the opposite direction or in a direction to carry thecrushing roller Sl outwardly away from the abrasive wheel 26. Thus, thecrusher roller is easily, quickly and accurately brought to activeposition and easily and quickly moved from such position.

Preferably means are provided for automatically swinging the arm 86 andthe parts carried thereby to such outward position when the sleeve isturned to present the low portion of cam |04 to the screw |02. To thedesired end, a bracket ||2 is shown as fastened to an edge por` tion ofthe bracket 2| and a bracket or clip ||3 is fastened to a portion ofhead 88. A coil spring ||4 is anchored at its respective ends to thesebrackets and the construction and arrangement is such that this springis constantly tending to rock the arm 85 in a clockwise direction or ina direction 'to carry the crushing roller 0l away from the abrasivewheel.

Assuming that the screw |02 is so adjusted that the crushing roller willbe forced against the abrasive wheel when the high portion of cam |04 isbrought under the sccrew, then in order to bring the roller against thewheel it is but necessary'to turn the sleeve |05 to present the highportion of cam |04 to the inner end of screw |02 (see Fig. 4) when thecrushing roller is forced against the abrasive wheel.

After the abrasive wheel has been dressed, the sleeve |05 is partiallyrotated so that the low portion of cam m4 is presented to the inner endof the screw m3. At such time, the spring ||4 causes rocking of the arm85 in a manner to keep the inner end of the screw against the cam and toshift the crusher roller outwardly away from the abrasive wheel.

The pivotal mounting for the arm 05 is generally designated H5 (see Fig.6) and prior to entering into a detailed description of the machinesoperation, the details of such pivotal mounting, which is also anadjustable mounting, are here given. Mounting i l5 includes a tubularopening ||6 formed through the bracket 2| and in which are located apair of bearing sleeves rotatably and slideably mounting a hollow member||8 comprising a tubular portion ilS located in the bearings and ancuter portion |20 of less diameter than the portion H0 and having ashoulder |25 at its inner end. The arm 86 is disposed on the reduceddiameter portion l|20 of the member I8. A cap |22 closes the outer endof the opening ||6 about the tubular part H9 A and holds a bearingsleeve within such opening. The inner end of the opening is closed by acap |23 which includes an inner tubular portion |24 having an inturnedange |25.

A nut or cap |26 is threaded in the outer end portion of said tubularportion |24. Received by said tubular portion and located between itsflange |25 and the cap |28 is a block I2? serving as an anchor for theinner end of a rotatable bar |28. Since such bar includes a vshoulder|29 against the outer side of the block |21 and has a nut |30 threadedthereon and against the inner side of said block, it will be Vclear thatthe bar is held against longitudinal movement by the block. However, thebar may turn relative to the block.

Bar |20 is of considerable length and extends outwardly through themember i8. On an outer portion of the bar is a tubular stem |3| turnablerelative to the bar and xed to the arm 8S as by screws E32. Fixed to theextreme outer end of the bar |28 is a hand piece |33 including a tubularportion |34 overlapping the outer end of the stem |3| and a head portion|35 adapted to be gripped to turn the bar.

Within the reduced Vdiameter portion |20 of the member H8 is a nut |36through which the bar |28 passes and having threaded engagement Cil withthe intermediate portion |31 of said bar. Nut |36 being located betweenthe inner end of the sleeve |3| and internal shoulder |38 of the member||`8 is incapable of movement longitudinally relative to said member. Aset screw l|39 passes'through the intermediate portion of the arm 8@ andthe reduced portion |20 of member H8 and at its inner end bears againsta locking lug or block |40 having threads formed thereon toA mesh withthe threads |31 of the bar |28.

With the described construction, it will be understood that on the screw|39 being tightened as the arm is rocked to carry the crushing roller 87toward and from the wheel 26, the entire pivotal mounting ||5 will be.rocked and all the parts will move together as a unit. However, thismounting of the varm 86 includes an adjustment for shifting the arm inthe direction of the longitudinal axis of the shaft 25 so as to disposeany particular crushing roller in line with any particular thickness ofabrasive wheel.

Thus, on loosening of the screw |39 and turning of the hand piece |35,the bar |28 will be rotated. However, such bar may not move.longitudinally, being anchored by the block |27. Therefore, as the baris turned, the nut |36 will be fed along the threads of the bar and willshift the member i i8 inwardly or outwardly in the bearings locating thearm 85 in the desired position. Thereafter, the screw |39 is tightenedto lock the parts in this new position.

in employing the means of the invention, when a new crusher roller isbeing placed in operation, its contour will be machined approximately tothat desired. Now the hardened crusher roller is brought into contactwith the periphery of the abrasive wheel. At this time, the crushingroller is power driven by the motor 97 but only at a slow speed and thegrinding wheel 26 is driven only by contact with the crushing roller.Continued feeding of the crusher' roller into the wheel produces on thewheel the obverse of the contour of the crusher roller on the wheelface.

This results in a savings in the use of the diamond or other toolcarried by the pantograph means and further results in rather rapidlybringing the abrasive wheel to approximately the desired contour. Thercughed out abrasive wheel is thereafter dressed in the conventionalmanner using the pantograph means. -The freshly dressed wheel being nowexactly correct in contour, the crusher roller is ground by the wheel toan exact shape. This is accomplished by bringing the crusher roller intocontact with 'the abrasive wheel while both'are power driven, thecrusher roller at this time being also driven at a relatively slowspeed. The crusher roller has been shifted Vinto engagement with theabrasive wheel by turning of the cam ll, the screw |32 being properlyadjusted to have the cam force the roller against the wheel. Also, itwill be understood that the member |58 will have been properly adjustedlongitudinally for locating the crusher roller in radial alignment withthe wheel. After the crusher roller is properly shaped, the cam isfurther rotated or is shifted back to bring its lower point under theinner end of the screw |02 whereupon the spring ||4 rocks the entirecrusher roller mounting in a clockwise direction to carry the crusherroller away from the abrasive wheel.

The formed abrasive wheel is now used in the regular manner and thecrusher roller is ready for use to redress the abrasive wheel whenevernecessary. One advantage of dressing the abrasive wheel by bringing thecrusher roller against the same is that a freer grinding surface isgenerated on the wheel by action of the crusher roller. There is theadditional advantage of saving wear on the pantograph mounted diamond orother tool. Further, the cooler grinding action obtained when using theroller crushed wheel results in less heating and distortion of the workpiece. This permits of the grinding of greater contour widths than wouldotherwise be possible without abnormal heating and distortion of thework piece.

When the crusher roller becomes worn or needs restoration of detail, itis re-ground as previously described by regenerating its contour with afreshly dressed abrasive wheel or with a wheel that has been freshlydressed using the pantograph means. When, in any instance, the rollercrushed grinding wheel fails to reproduce sufficient fidelity of detailon the work, the wheel is dressed directly from the template by means ofthe pantograph mounted diamond or other tool providing' greater accuracythrough elimination of the intermediate step of grinding the roller andthereafter using the latter to form the wheel.

In all of the described operations the maintenance of relative locationsof the contour on the template, wheel, crusher roller and work isinherent in the construction of the device. All of these structures,with the exception of the template, are mounted on the bracket 2l or onthe table i I. Thus, any adjustment of the entire pantograph means byadjustment of the bracket 2! identically adjusts the wheel 2E and theroller 8l. The machine provides for the enjoyment of the advantages ofeither method of wheel dressing; that is, by the diamond or by thecrushing roller, the structure for the performance of both methods beingincorporated in the same machine and being quickly available foroptional use without loss of relative location. The present constructionpermits the contour to be ground on the crusher roller while it ismounted on the bearings on which it is mounted when it is used to crushthe wheel. This provides for accuracy by eliminating the errorsresulting from changing the roller from one shaft or bearing to another.

To sum up briefly the advantages of the present construction, it ispointed out that heretofore forming of wheels for contour grinding hasbeen done by either of two methods; namely, (l) roller crusher dressing;and (2) diamond dressing. There are inherent advantages anddisadvantages in both methods. The present invention provides for orfacilitates the use of either method at any time the operator maychoose. This permits the operator to easily take advantage of the methodmost desirable at any particular time or for any particular job.

The entire pantograph means and the parts mounted thereon, together withthe entire crushing roller means and its associated parts, are mountedon the movable wheel head so that when the latter is adjusted thedressing mechanisms remain in the same relation to the abrasive wheel asprevious to any such adjustment. Movement of the slide d4 by thecalibrated screw means described causes feeding of the entire pantographmeans into or toward the abrasive wheel a measured amount or an amountreadily determined from a reading of the micrometer scale 3l. Thisfeeding of the slide 32 moves the tool or diamond toward the abrasivewheel and governs stock removal therefrom.

However, it is pointed out that the arm 8B and the crushing roller meanscarried thereby are not mounted on the slide 34 but are mounted on thebracket 2| on which said slide is mounted. Therefore, adjustments of theslide 3d do not result in any change in position of the crushing rollermechanism relative to the grinding wheel.

The slide d2 is adjustable at right angles to the slide 3d and permitsoffsetting of the entire pantograph means so that the same may be swungto position the diamond laterally of the abrasive wheel for forming anddressing contours on the side of the latter as well as on the edge orface thereof, when such is necessary or desired.

However, adjustments of slide 42 have no bearing on the crushing rollerand its associated parts since regardless of any adjustments of saidslide, the crushing roller and associated parts remain in the samerelation to the grinding wheel. The mechanism as already described, maybe used for the abrading of cemented tungsten carbide and the presentinvention includes a method of forming an abrasive device adapted forthe form grinding of cemented tungsten carbide.

When cemented tungsten carbide is to be form ground a disc or wheel ofbrass or similar metal is mounted on the shaft 25 in place of theabrasive wheel shown. Such disc may be previously roughly dressed tothedesired contour and if so, it is finished dressed by use of a cementedtungsten carbide tool or the like in the holder S2. Such tool, ofcourse, will be operated through the pantograph means. When the brass orother disc is properly formed, the formed crusher roller is brought inagainst the edge of the disc and diamond dust placed on the edge of thebrass disc.

This diamond dust is forced into the disc by the hardened and formedcrusher roller. Thereafter cam |04 is shifted to permit of spring Ilacarrying the crusher roller away from the brass disc and the latter isready for use in the form grinding of cemented tungsten carbide. Whenthe brass disc loses the detail of its form, it is necessary to cut awayits periphery since while some diamond dust remains in its peripheralportion it may not be properly dressed. Its periphn ery is again formedand diamond dust spread thereon and forced therein by bringing thehardened, formed crusher roller thereagainst :as previously described.

Having thus set forth the nature of my invention, what I claim is:

1. In a grinding machine, a base, a horizontal work table on said base,a vertical column on said base at the rear side of said table andextending above the latter, a wheel head, means mounting said wheel headon the forward side of said column and for vertical adjustment thereon,a horizontal abrasive wheel mounting shaft supported by said head formovement therewith and eX- tending forwardly of said head over saidtable, a wheel dressing means comprising an arm, means mounting said armon the forward side of said head in a position laterally of said shaftfor vertical adjustment with said head, said means comprising pivotingmeans located intermediate the ends of said arm and mounting the sainefor pivotal movement to carry the lower end of the arm laterally towardand from the peripheral edge of an abrasive wheel on said wheel mountingshaft, a shaft mounted lby the lower end of said arm in parallelrelation with the wheel vmounting` shaft, a peripherally contouredhardelectric motor on said arm and connected to drive said crusherroller, a cam rotatably mounted on the forward side of said wheel headadjacent the upper end of said arm for vertical adjustmentY with saidwheel head and for turning movement relative thereto, a screw on theupper end of said arm and normally engaging said cam whereby on turningmovement of the cam said; arm is rocked on its pivotal mounting to shiftsaid crusherI roller and force its peripheral edge into crushingengagement with the peripheral edge of a wheel on said Wheel mountingshaft to form dress said wheel, said arm mounting means comprising atubular shaft having bearing in said tool head and extending forwardlyofthe forward face of said tool head, a rod extending longitudinallythrough said tubular shaft, meansl mounting said rod for turningmovement about its longitudinal axis and against longitudinal movement,means forming a threaded engagement between said rod and said shaftwhereby' on turning of the rod on its longitudinal axis the shaft isadjusted axially to shift said arm and thereby said Crusher rollerforward-ly and rearwardly in the direction of the length of the abrasiveWheel mounting shaft, and means to lock said arm mounting shaft andthereby said arm in forwardly and rearwardly adjusted positions..

2. In a grinding machine, a vertically adjustable wheel head supportingan abrasive wheel mounting shaft, a wheel dressing means on said wheelhead comprising an arm, means mounting said arm on the wheel head forvertical adjust.- ment therewith and for pivotal movement relativethereto to carry the lower end of the arm toward and from the peripheraledge of an abra- Sil/ev wheel on said wheel mounting shaft, a shaftmounted' by the lower end of said arm in parallelv relation to the wheelmounting shaft, a peripherally contoured hardened cylindrical steelmember constituting a crusher roller on the second mentioned shaft, anelectric motor on said arm below said pivotal mounting and connected todrive said Crusher roller, a, manually rotatable cam mounted on saidwheel head and vertically adjustable therewith and turnabl'e relativethereto, spring means normally biasing said arm in one direction aboutits pivotal mounting, a Screw on the upper end of said arm and normallyheld in engagement with said cam by the biasing action of said springmeans whereby on turning move- `ment of the cam the arm is rocked on itspivotal mounting against thev action of said spring means to shift saidcrusher roller to bring its peripheral edge into crushing engagementwith the peripheral'edge of a wheel on said wheel mounting shaft` toform dress said wheel, said arm mounting means comprising a tubularshaft having bearing in said tool head and extending forwardly of theforward face of the tool head, a rod extending longitudinally throughsaid tubular shaft, means mounting said rod for turning movement aboutits longitudinal axis and against longitudinal movement, means forming athreaded engagement between said rod and said shaft whereby on turningof the rod on its longitudinal axis the shaft is adjusted to shift saidarm and thereby said Crusher roller laterally in the direction of thelength of the abrasive Wheel mounting shaft to locate said Crusherroller for engagement of different axial portions of its periphery withsaid abrasive wheel, and means to secure said arm and thereby saidcrusher roller in its adjusted position.

FLOYD E. HAWLEY.

REFERENCES CITED The following references are of record in the 35 fileof this patent:

UNITED STATES PATENTS

